1. Technical Field
The present invention relates to an image display device and method, and more particularly, to a false contour correction apparatus in an image display system, by which a false contour at a place where conversion of the unit bits of data is severe on a display device driven in a digital system can be corrected.
2. Related Art
Existing types of display devices driven in a digital system include a plasma display panel (PDP), a liquid crystal display (LCD) panel, a ferroelectric liquid crystal (FLC) panel, and the like.
FLC panels have a structure in which ferroelectric liquid crystal is sandwiched between an optical planar mirror formed on a silicon substrate and glass, and have a wide viewing angle and a fast response speed compared to other panels.
In a display device driven in a digital system, distortion of picture due to an optical illusion, which is referred to as a false contour, usually occurs at a place where conversion of the unit bits of data is severe.
In a display apparatus driven in a digital system, a false contour having serious bit conversion is generated on a changing picture, for example, at the gentle boundary where a data value is changed from 63 to 64 and from 127 to 128. That is, even when a data value is change just by one, for example, from 127 to 128, if a picture changes, data of 225 or 0 is perceived at the boundary according to the direction of the movement of the picture, resulting in a fatal degradation in the quality of image.
I have found that an image can be degraded to an undesirable level due to the false contour phenomenon. Efforts have been made to reduce false contouring and improve image display systems.
Exemplars of recent efforts in the art include U.S. Pat. No. 6,072,555 to Mizutome et al., entitled DISPLAY APPARATUS CAPABLE OF GRADATIONAL DISPLAY, issued on Jun. 6, 2000, U.S. Pat. No. 5,963,190 to Tsuboyama et al., entitled DRIVING METHOD FOR DISPLAY DEVICE AND DISPLAY APPARATUS, issued on Oct. 5, 1999, U.S. Pat. No. 6,088,012 to Shigeta et al., entitled HALF TONE DISPLAY METHOD FOR A DISPLAY PANEL, issued on Jul. 11, 2000, U.S. Pat. No. 6,052,112 to Tanaka et al., entitled GRADATION DISPLAY SYSTEM, issued on Apr. 18, 2000, U.S. Pat. No. 5,109,282 to Peli, entitled HALFTONE IMAGING METHOD AND APPARATUS UTILIZING PYRAMIDOL ERROR CONVERGENCE, issued on Apr. 28, 1992, U.S. Pat. No. 6,100,939 to Kougami et al., entitled TONE DISPLAY METHOD AND APPARATUS FOR DISPLAYING IMAGE SIGNAL, issued on Aug. 8, 2000, U.S. Pat. No. 6,018,329 to Kida et al., entitled DRIVING SYSTEM FOR A PLASMA DISPLAY PANEL, issued on Jan. 25, 2000, U.S. Pat. No. 4,574,636 to Satake, entitled APPARATUS FOR EXAMINING AN OBJECT BY USING ULTRASONIC BEAMS, issued on Mar. 11, 1986, U.S. Pat. No. 6,134,025 to Takeuchi et al, entitled DOT IMAGE DATA OUTPUT APPARATUS, issued on Oct. 17, 2000, U.S. Pat. No. 5,706,063 to Hong, entitled OPTICAL SYSTEM OF A REFLECTION LCD PROJECTOR, issued on Jan. 6, 1998; Japanese Patent No. 11-6980 to Miyashita, entitled PROJECTION DEVICE, published on Jan. 12, 1999, Japanese Patent No. 8-168039 too Nomura et al., entitled PROJECTION DISPLAY SYSTEM AND PROJECTION POSITION ADJUSTING METHOD, published on 25 Jun. 1996, Japanese Patent No. 09-90402 to Takigawa et al., entitled PICTURE DISPLAY DEVICE, published on 4 Apr. 1997, Japanese Patent No. 10-123477 to Yoneda et al., entitled LIQUID CRYSTAL PROJECTOR, published on 15 May 1998, Japanese Patent No. 10-23445 to Semasa, entitled PICTURE DISPLAY DEVICE, published on 23 Jan. 1998, Japanese Patent No. 08-294138 to Ozuru et al., entitled LIQUID CRYSTAL PROJECTOR, published on 5 Nov. 1996, and Japanese Patent No. 10-148885 to Murakami et al., entitled PROJECTOR APPARATUS, issued on 2 Jun. 1998.
While these recent efforts provide advantages, I note that they fail to adequately provide a false contour correction apparatus and method in an image display system.